Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
736 FXUS64 KHGX 161149 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 649 AM CDT Wed Sep 16 2026 ...New AVIATION... .KEY MESSAGES... - Isolated showers and thunderstorms continue Wednesday. - More widespread showers and thunderstorms Thursday, with highest chances along the coast. - Hot and humid conditions generally continue into the weekend, with highs in the low-to-mid 90s. && .DISCUSSION... Issued at 1025 PM CDT Tue Sep 15 2026 Little change is expected for Wednesday. A broad upper ridge will slowly shift westward and resultant capping will inhibit any widespread convective initiation. Latest CAMs indicate some onshore isolated thunderstorms developing through the morning hours generally west of San Luis Pass and potentially moving farther inland by afternoon. In any case, these should not amount to much and most locations will stay dry. Although there is currently no Heat Advisory issued, heat indicies will approach the 108F mark, particularly for areas south and east within the forecast area. Continue to use caution if engaging in outdoor activities. After a quiet Wednesday night time frame, a surge of tropical moisture remains expected to move into the area on Thursday morning. PWATs are still impressive, generally ranging from 2.1-2.4". This will lead to more widespread showers and thunderstorms, with highest chances along the coast and becoming lower as you move northward. The high moisture parameters persist through the afternoon although may diminish sooner than models indicate with increased capping/subsidence due to the aforementioned ridge. Nonetheless locally heavy downpours are possible most everywhere in the forecast area. Use caution on the morning/evening commutes. Precipitation should gradually taper off in the evening as more dry air builds in from the east. The dry air will bring some minor relief and conditions will be slightly less humid on Friday, with heat indicies topping out near 100. The upper ridge will become more elongated from southwest to northeast and get squeezed in between strengthening low pressure over Florida and a broad trough encompassing much of the western half of CONUS. This setup would not even yield much in the way of diurnal convection and thus a generally quiet albeit another hot and humid weekend looks to be in store. Precipitation chances may increase Sunday into next week as the upper ridge begins to weaken. && .AVIATION... (12Z TAF Issuance) Issued at 646 AM CDT Wed Sep 16 2026 VFR conditions at all sites this morning. Radar showing a few showers popping up along the coast this morning. Expect this trend of isolated showers to continue again today through the morning hours with isolated thunderstorms possible again this afternoon. Any activity should taper off near sunset with the loss of daytime heating. Winds will be light out of the southeast through the period. Bailey && .MARINE... Issued at 1025 PM CDT Tue Sep 15 2026 Light SE winds will back to due easterly this morning and increase to around 15 kts by the afternoon. These will slightly diminish overnight, before increasing again on Thursday afternoon to around 20 kts. Winds will diminish by Friday to near 15 kts and further diminish into the weekend. Seas of 2 to 3 ft will gradually build to 4 to 6 ft from west to east on Thursday morning, before slightly subsiding to 3 to 5 ft Friday morning and further into the weekend. Isolated-to-scattered thunderstorms remain possible, however are expected to be much more widespread on Thursday. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 98 77 97 75 / 0 0 20 0 Houston (IAH) 96 79 93 77 / 20 10 30 0 Galveston (GLS) 92 83 90 83 / 20 30 70 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...AP AVIATION...Bailey MARINE...AP